Intro LCA Flashcards
What are the phases of the LCA?
Goal & Scope
Inventory Analysis
Impact Assessment
Interpretation
What are examples of inputs?
Land, crude oil, water, wood, etc.
What are examples of outputs?
CO2, pesticides, waste, etc.
What are examples of midpoints?
Climate change photochemical oxidation ozone depletion acidification eutrophication human toxicity eco toxicity water use land use resource use.
What is the definition of a midpoint?
Problems
Methodological tool used for decision making, quantifies potential environmental impacts
What are examples of endpoints?
Human health
Ecosystem quality
Resources and ecosystem services
What is the definition of an endpoint?
Damages on areas of protection
Methodological tool used for decision making, quantifies potential environmental impacts
What is the Goal definition?
Intended Application (ex. product dev and improvement, etc.)
Reasons for carrying out the study
Intended audience
What is the Scope definition?
Function, functional unit, and reference flow Initial choices (system boundaries, data quality) Critical review and other procedural aspects
Define function and its importance?
What the object is used for
Primary vs. Secondary functions
For a comparison, both systems must have the same function
Define functional unit?
Quantitative description of the function or service for which the assessment is performed, and the basis of determining the reference flow of product that scales the data collection in the next LCA phase, the inventory analysis.
Ex. Wear a pair of jeans every day for 5 years in India
What is the definition of an elementary flow?
Linking unit processes with the environment
What is the definition of an intermediary flow?
Linking unit processes to each other
What is the definition of an economical flow?
Man-made
What are the rules of system boundaries?
- Compared systems must provide the same function
- Identical stages/processes between compared systems can be excluded ONLY IF this does not affect their functional equivalence
- Include processes that meet a chosen cut-off criteria
How do you define the system boundaries?
Selecting the geographical and temporal boundaries and settings of the study
and the level of technology that is relevant for the processes in the product
system.
What is the inventory analysis? What is its purpose?
The inventory analysis collects information about the physical flows in terms of input of resources, materials, semi-products and products and the output of emissions, waste and valuable products for the product system.
The outcome of inventory analysis is the life cycle inventory
What is the first step of impact assessment?
Selection:
Select impact categories representative of the assessment/key parameters that were chosen as a part of the scope definition.
What is the second step of impact assessment?
Classification:
Assign elementary flows from the inventory to impact categories according to their ability to contribute by impacting the chosen indicator
What is the third step of impact assessment?
Characterization:
Using environmental models for the impact category to quantify the ability of each of the assigned elementary flows to impact the indicator of the category.
Impact scores are a common metric for impact category.
What is the fourth step of impact assessment?
Normalization:
Used to inform about the relative magnitude of each of the characterized scores for the different impact categories by expressing them relative to a common set of reference impact (one ref impact per impact category)
What is the fourth step of impact assessment?
Grouping/Weighting:
Supports comparison across the impact categories by grouping and possibly ranking them according to their perceived severity, or by weighting them using weighting factors that for each impact category gives a quantitative expression of how sever it is relative to other impact categories.
Allows you to get one overall impact score for the product systems
What are the components of interpretation?
Identify significant issues
Evaluate study for completeness, consistency, sensitivity
Conclusions, recommendations
What are the limits of LCA?
The assessed impacts are the POTENTIAL impacts, not real impacts (exceeding of thresholds, safety margins or risks)
This is due to:
- Relative expression of impact scores related to a reference unit
- Integration of environmental data over space and time
- Inherent uncertainty in modelling of impacts
Not all processes or flows are modelled (or have unrepresentative data)
What are the benefits of LCA?
Public Policy Making
Reaching objectives Kyoto protocol
Possibility for ecolabelling or environmental product declaration
